1. Technical Field
The invention relates to an electro-optical device and an electronic apparatus, and more particularly, to an electro-optical device which includes a color filter having a plurality of colored layers and allows both reflective display and transmissive display of colors to be implemented by the color filter.
2. Related Art
In general, a color filter is provided for allowing color display to be performed in a liquid crystal display (LCD) or other various electro-optical devices. This color filter is, for example, formed such that a plurality of, different colored layers, such as, red, green, and blue colored layers, are respectively disposed in every pixel and the plurality of colored layers are arranged in a predetermined pattern. Such colored layers are formed, for example, by a photolithography method using a photosensitive resin containing colorant (e.g., pigment, dye, or the like).
In the meantime, there is a known display device, which has a backlight disposed at the rear side of the electro-optical device to display the visible transmission by using lights of the backlight in a relatively dark environment such as indoors or in the car, and turns off the backlight to display visible reflection by using external lights in a bright location such as outdoors. In this type of device, a transmitting region allowing lights to be transmitted and a reflecting region allowing lights to be reflected are formed within each pixel, and the transmissive display is utilized by using the transmitting region and the reflective display is utilized by using the reflecting region.
In this case, the colored layer needs to be formed at both sides of the transmitting and reflecting regions in order to utilize the color display at both sides thereof, however, lights from the backlight transmit the colored layer in the transmitting region only once whereas external light transmit the colored layer twice by going and returning, such that bright display is possible at the expense of saturation in the transmissive display, and it is easy to increase the saturation at the expense of bright display in the reflective display. Accordingly, the colored layer in the transmitting region generally needs to have higher saturation than the colored layer of the reflecting region.
In order to have colored layers with different saturations from each other in the transmitting and reflecting regions, an amount of colorants contained in the colored layer should be changed, such that the different kinds of the colored layers cause a manufacture process thereof to be complicated. Here, there is a well-known color filter for an LCD. The color filter has colored layers with two colors stacked sequentially in the transmitting region among three complementary colors of cyan, magenta, and yellow while having each of the two colors disposed as a single layer in the reflecting region in order to form three primary colors of red, green, and blue colors such that a saturation for the transmissive display can be secured and a brightness of the reflective display can be obtained (for example, see JP-A-2002-258029).
However, in the electro-optical device which allows both the transmissive display and the reflective display to be utilized, a substantial aperture ratio of the transmissive display decreases due to the formation of the reflecting region while a substantial aperture ratio of the reflective display simultaneously decreases due to the formation of the transmitting region, such that it is difficult to secure display brightness and utilize a visual balance between both reflective display and transmissive display.
In particular, a luminance or a contrast of the reflective display is originally and significantly lower than a luminance or a contrast of the transmissive display, such that the reflecting region is given priority so as to secure brightness whereas a high display quality (e.g., a contrast, color reproducibility, or the like) is required for the transmissive display. Thus, it is necessary to improve the quality of the color filter in the transmitting region having a limited area in order to improve the display quality of the transmissive display. However, when the colored layers of the reflecting and transmitting regions are formed of different materials to perform high quality transmissive display, the number of process steps of manufacturing the color filter increases, which causes an increase in manufacturing cost.